Trial Review

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Trial registered on ANZCTR


Registration number
Help: Registration number
ACTRN12626001123336p
Ethics application status
Help: Ethics application status
Submitted, not yet approved
Date submitted
Help: Date submitted
10/08/2026
Date registered
Help: Date registered
10/09/2026
Date last updated
Help: Date last updated
10/09/2026
Date data sharing statement initially provided
Help: Data sharing statement date
10/09/2026
Type of registration
Help: Type of registration
Prospectively registered

Titles & IDs
Public title
Best of Both (BOB) Trial: A Feasibility Study of Hybrid High Dose Rate Brachytherapy and Stereotactic Ablative Body Radiotherapy for Low- and Intermediate-Risk Prostate Cancer
Scientific title
Best of Both (BOB) Trial: A Feasibility Study of Hybrid High Dose Rate Brachytherapy and Stereotactic Ablative Body Radiotherapy for Low- and Intermediate-Risk Prostate Cancer
Additional trial identifiers [1] 317686 0
Nil
Universal Trial Number (UTN)
Trial acronym
BOB
Related trial records

Health condition
Health condition(s) studied:
Prostate cancer 342504 0
Condition category
Condition code
Cancer 338634 338634 0 0
Prostate

Intervention/exposure
Study type
Interventional
Description of the intervention or exposure
This is a single arm study. All participants will receive 1 administration of high dose rate (HDR) brachytherapy and 1 fraction of stereotactic ablative body radiotherapy (SABR).

HDR brachytherapy is a form of radiation treatment. Under general or spinal anaesthesia, patients will have a urinary catheter inserted, and placement of a rectal spacer between the prostate and rectum to reduce radiation exposure to the rectum. Then 18-22 thin hollow needles will be inserted into the prostate through the perineum, through which a radiation source will be passed to deliver radiation directly to the prostate. After radiation, all needles will be removed, and three small gold markers, about the size of a grain of rice, will be implanted into the prostate. These will act as a permanent high contrast reference point during the SABR treatment.
HDR dose will be 13.5 Gy delivered in a single fraction (treatment session). The procedure typically takes 2-4 hours. Participants will remain in hospital overnight for observation. Once bleeding has settled (usually the day after HDR brachytherapy), participants will have a CT scan and MRI so that the SABR treatment can be planned. The catheter will be removed after this, and once confirmed that the participant can empty their bladder adequately, they will be discharged from the hospital.

SABR will be delivered approximately 3-4 weeks after the HDR brachytherapy.
Participants will be treated as an outpatient. They will be positioned on the treatment couch in the same position as the CT and MRI performed after their HDR brachytherapy, using the gold markers for image guidance. They will receive a single fraction of external beam radiation treatment delivered by a linear accelerator. The dose received will be 13.5 Gy. This treatment is expected to take 20-30 minutes, however patients may be at the treatment centre for up to 2 hours to allow for preparation, positioning and treatment verification. After treatment participants can then return home.

Treatment will be prescribed and overseen by a qualified Radiation Oncologist.

Adherence to treatment will be monitored through participants' medical records.

After treatment is complete, participants will commence follow up. This may be completed in clinic, or remotely via technology such as telephone or telehealth.
The first follow up appointment will be the 'safety follow up', occurring 5-6 weeks after SABR. For the first year, participants will then be followed up every 3 months. In the second year, participants will be seen every 6 months, and this will complete trial involvement.
Intervention code [1] 334520 0
Treatment: Other
Description of the comparator or control
No control group
Control group
Uncontrolled

Outcomes
Primary outcome [1] 346384 0
Patients completed hybrid treatment without a grade 3 or higher toxicity within 3 months of SABR
Timepoint [1] 346384 0
Adverse events will be assessed during treatment and at every follow up review until 24 months after SABR.
Secondary outcome [1] 465931 0
Rate of acute genitourinary toxicity
Timepoint [1] 465931 0
Adverse events will be assessed during treatment and at every follow up review until 24 months after SABR. Events will be considered "acute" if occurring during treatment and up to the safety follow up.
Secondary outcome [2] 465932 0
Rate of late genitourinary toxicities
Timepoint [2] 465932 0
Adverse events will be assessed during treatment and at every follow up review until 24 months after SABR. Events will be considered "late" if they occur after the safety follow up visit.
Secondary outcome [3] 465933 0
Late quality of life
Timepoint [3] 465933 0
Quality of life will be assessed at baseline, safety followup, then at every follow up until 24 months after SABR.
Secondary outcome [4] 465934 0
Rates of prostate-specific antigen (PSA) bounce
Timepoint [4] 465934 0
PSA will be measured at baseline, safety follow up and every follow up until 24 months after SABR
Secondary outcome [5] 465935 0
PSA value of less than 0.4ng/mL at 2 years
Timepoint [5] 465935 0
Baseline, safety follow up, and every follow up review until 24 months after SABR
Secondary outcome [6] 465936 0
Biochemical disease-free survival
Timepoint [6] 465936 0
baseline, safety follow up, and every follow up review until 24 months after SABR
Secondary outcome [7] 465937 0
Time cost of travel
Timepoint [7] 465937 0
Calculated at safety follow up
Secondary outcome [8] 465938 0
Financial cost of hybrid treatment compared to standard treatment
Timepoint [8] 465938 0
Assessed at end of study
Secondary outcome [9] 465939 0
Carbon footprint assessment
Timepoint [9] 465939 0
Assessed at end of study
Secondary outcome [10] 466894 0
Rate of acute gastrointestinal toxicity
Timepoint [10] 466894 0
Adverse events will be assessed during treatment and at every follow up review until 24 months after SABR. Events will be considered "acute" if occurring during treatment and up to the safety follow up.
Secondary outcome [11] 466896 0
Rate of late gastrointestinal toxicities
Timepoint [11] 466896 0
Adverse events will be assessed during treatment and at every follow up review until 24 months after SABR. Events will be considered "late" if they occur after the safety follow up visit.
Secondary outcome [12] 466897 0
Late quality of life
Timepoint [12] 466897 0
Quality of life will be assessed at baseline, safety follow up, then at every follow up until 24 months after SABR
Secondary outcome [13] 466900 0
Rates of PSA decline
Timepoint [13] 466900 0
PSA will be measured at baseline, safety follow up and every follow up until 24 months after SABR
Secondary outcome [14] 466901 0
Time cost of treatment
Timepoint [14] 466901 0
Calculated at safety follow up

Eligibility
Key inclusion criteria
* low- or intermediate-risk prostate cancer (International Society of Urological Pathology Grade Group 1-3, PSA no more than 20ng/mL, clinical stage T1-2c)
* Eastern Co-operative Oncology Group (ECOG) 0-1
* Not on alpha-adrenergic inhibitor or anticholinergic drugs
* International Prostate Symptom Score (IPSS) <15
* Suitable for general or spinal anaesthesia as determined by treating clinician
Minimum age
18 Years
Maximum age
No limit
Sex
Males
Healthy volunteers
No
Key exclusion criteria
* prior pelvic radiotherapy
* bleeding diathesis or use of anti-coagulation that is unsafe to discontinue for fiducial marker, rectal spacer administration and HDR brachytherapy
* prostate gland >60cc
* hip prosthesis or other pelvic metalwork that may cause artefact on magnetic resonance imaging

Study design
Purpose of the study
Treatment
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Single group
Other design features
Phase
Not Applicable
Type of endpoint/s
Safety
Statistical methods / analysis
This is a preliminary feasibility study, and sample size is based on pragmatic considerations of expected clinical throughput at the trial site over a 2-year period; formal power calculations are not applicable.

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
1/10/2026
Actual
Date of last participant enrolment
Anticipated
1/10/2028
Actual
Date of last data collection
Anticipated
1/10/2030
Actual
Sample size
Target
20
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
VIC
Recruitment hospital [1] 29973 0
Peter MacCallum Cancer Centre - Melbourne
Recruitment postcode(s) [1] 46358 0
3000 - Melbourne

Funding & Sponsors
Funding source category [1] 322228 0
Charities/Societies/Foundations
Name [1] 322228 0
Peter Mac Foundation
Country [1] 322228 0
Australia
Primary sponsor type
Hospital
Name
Peter MacCallum Cancer Centre
Address
Country
Australia
Secondary sponsor category [1] 325134 0
None
Name [1] 325134 0
Address [1] 325134 0
Country [1] 325134 0

Ethics approval
Ethics application status
Submitted, not yet approved
Ethics committee name [1] 320751 0
Peter MacCallum Cancer Centre Human Research Ethics Committee
Ethics committee address [1] 320751 0
Ethics committee country [1] 320751 0
Australia
Date submitted for ethics approval [1] 320751 0
10/08/2026
Approval date [1] 320751 0
Ethics approval number [1] 320751 0

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 151498 0
Dr David Chang
Address 151498 0
Peter MacCallum Cancer Centre, 305 Grattan Street, Melbourne VIC 3000
Country 151498 0
Australia
Phone 151498 0
+61385598566
Fax 151498 0
Email 151498 0
[email protected]
Contact person for public queries
Name 151499 0
David Chang
Address 151499 0
Peter MacCallum Cancer Centre, 305 Grattan Street, Melbourne VIC 3000
Country 151499 0
Australia
Phone 151499 0
+61385598566
Fax 151499 0
Email 151499 0
[email protected]
Contact person for scientific queries
Name 151500 0
David Chang
Address 151500 0
Peter MacCallum Cancer Centre, 305 Grattan Street, Melbourne VIC 3000
Country 151500 0
Australia
Phone 151500 0
+61385598566
Fax 151500 0
Email 151500 0
[email protected]

Data sharing statement
Will the study consider sharing individual participant data?
No


What supporting documents are/will be available?

No Supporting Document Provided


Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.